How to fix Cloth Simulation from this odd compression
If the fabric curls up like this or explodes the collision detection is usually to blame. But it takes only a few steps to fix this.

Add a floor: Add a plane, scale it up, add &amp; apply a Subdivision modifier (3 levels, type: Simple), and add a Collision physics to it
Fix the door:

Swap the order of the modifiers to 1. Subdivison, 2. Cloth ←→ 3. Solidify
Change the levels of the Subdivision modifier: 2 (Viewport) and 2 (Render)
In the Physics tab, use the Silk preset. For some reason, your door plane is way too stiff. (Presets are in the drop-down menu right next to the Cloth section; the icon with 3 dots and lines).
Change the Distance of Object Collision and Self Collision from 15 cm to 5 mm (0.005 m). The default value of 15 cm is too high for your tent in real-world size.


Optimization: Remove the Collision from the 2 branches objects. It has no effect on the result since the fabric slides only briefly over the left branch and is attached to the right branch anyway. But the removal will speed up the simulation.
Run the simulation. It should run smoothly. If you get single vertices that go crazy for a second (&quot;spikes&quot;/&quot;fireworks&quot;) increase the Cloth → Quality Steps from 5 to 9 and they should calm down.